Although stereoscopic vision was first described by the Greek mathematician Euclid (280 BC), it was not until the 1830s that Charles Wheatstone (inventor of the linear motor and concertina) described a device for the stereoscopic display of visual informations (Figure 2-2). Wheatstone's experiments were limited to drawings, because the photographic medium of his time, the daguerreotype, was difficult to illuminate evenly and could not produce sufficiently matched images because of long exposure times. In 1850, Brewster developed a stereoscope that used lenses for the direct viewing of photographs placed in a darkened box6 (Figure 2-3). Stereo viewing became a popular parlor pastime in Victorian England after Brewster introduced his lenticular stereoscope at the Great Exhibition of 1851.7 It was popularized in the United States after Oliver Wendell Holmes Sr. (physician, poet, and essayist) developed the familiar Holmes stereoscope.8A Holmes stereoscope could be used to appreciate, for example, the elaborate set of stereo fundus paintings that was published in three volumes by Oatman in 19138 (Figure 2-4).

FIGURE 2-2. An example of Wheatstone's original drawings pre-sented as an anaglyph. (Reprinted with permission from J Jones. Wonders of the Stereoscope. New York: Knopf, 1976.)

FIGURE 2-3. Brewster's stereo viewer remarkably resembles what we still use today. (Reprinted with permission from J Jones. Wonders of the Stereoscope. New York: Knopf, 1976.)

Sequential stereoscopic fundus photographs were first published in 1909, by Thorner9 (Figure 2-5). His elaborate technique called for, among other complications, flipping the camera upside down between exposures. A more practical sequential technique that involved side-to-side shifting was devised by Metzger in 1926.10 Simultaneous stereo fundus photography was introduced by Norton in 1953, although his fundus camera, which was based on the indirect ophthalmoscope, never became commercially available.11,12 The camera developed by Donaldson in 1964 used two sets of rhomboid prisms to split the light from a single front lens and direct it toward two different frames of film13 (Figure 2-6). Variations on this design are still used in the simultaneous stereo fundus camera manufactured by Nidek, Topcon, and Zeiss-Humphrey.

FIGURE 2-6. A diagram of the Donaldson simultaneous stereoscopic fundus camera, which exposed a stereo pair with a single flash. (After an illustration from the operating instructions for the Donaldson simultaneous stereoscopic fundus camera.)

The first atlas of stereoscopic fundus photographs, in which descriptive text alternates with original photographic prints, was published in two volumes by Bedell in 1929.14 Bothman and Bennett's 1939 atlas, Stereoscopic Photographs of the Fundus Oculi, uses original photographs pasted on stereoscopic cards in a manner rem-iniscent of Oatman's work.15 In 1964, Blodi and Allen introduced View-Master reels as a method of reproducing stereoscopic retinal images for textbooks.16 Despite mediocre viewers and small, high-contrast images, this stereo reproduction technique was used throughout the 1970s. Another strategy that has gained popularity is to present 2 x 2 in., side-by-side images packaged with an inexpensive cardboard viewer, which significantly reduces the cost of producing an atlas compared to the expense of multiple View-Master reels.17

This book is the first ophthalmic atlas to use computer-generated anaglyphs to convey stereo angiographic information.